Along with the increased flexibilization of the labour market in Europe, there has been a change in the permanence and security of employment. Job insecurity is constituted by a subjectively experienced threat of having to give up one's job sooner than one would like. The experience of job insecurity has been linked to decreasing well-being, negative attitudes towards one's job and organization, and reluctance to stay with the organization. The present study investigates what groups experience higher levels of job insecurity than others. Survey data from four European countries (Belgium, Italy, the Netherlands and Sweden) were used to determine what characterizes individuals who experience high levels of job insecurity. The results show that employees in jobs characterized by manual labour, contingent workers, and to some extent older workers and those with lower levels of education, experience higher levels of job insecurity.